The present invention relates to a device for the interconnection of a ski binding to a ski.
Known types of ski bindings usually comprise a toe unit and a heel unit, which are designed for temporary clamping a ski boot to the ski. Such known types of ski bindings provide an interconnection of the toe unit and the heel unit to the ski through known type mechanical means for example screws. The toe unit and the heel unit are connected to the ski in such a way that the mutual distances between them is proportional to the size of the ski boot being used. This distance is necessarily variable so that it can be adapted to a variation in the ski boot size.
When the ski is loaned to a different user with a different foot size or when the size of the user's foot increases (as for example when the user is a child), it is necessary to make additional holes in the ski in order to allow the interconnection of the toe unit and/or the heel units in a new position, compatible with the new size of the user's foot.
The main drawback of such known type of ski bindings consists in that drilling and shifting the toe and/or the heel unit is not only burdensome and laborious, but necessarily involves a weakening of the structure of the ski and diminution of its reliability.
As a partial remedy of such drawbacks, it is known to manufacture ski bindings designed to allow a partial shifting of the toe unit and/or the heel unit along the longitudinal axis of the ski, thereby allowing the user to perform a variation in the size without necessarily having to make new holes in the ski. Such known types of ski bindings, however, have the drawback of being often structurally complex and consequently very expensive and particularly subject to malfunctioning and possible breaking. Another disadvantage of such known ski bindings consists in that they offer a relatively small adjustment in size, usually suitable for covering two or three sizes at the most. This entails that the ski hire services must necessarily have a wide stock, with skis of various types and lengths, each of which must be fitted with ski bindings having different sizes one from another in order to cover a wide range of possible users. A further shortcoming is that many known types of these ski bindings do not allow an adequate longitudinal flexibility of the ski in the central area, thereby limiting the absorption of the stress given by unevenness of the snowy surface while skiing and therefore increasing the difficulty of practicing the sports.
A further drawback that these known ski bindings is that they require, at the time of purchase, the work of a specialised technician for mounting the ski bindings on the ski and, therefore, they entail a remarkable increase in purchase cost. Yet another shortcoming consists in that it is difficult to remove the ski binding once it is installed, so as to facilitate its transportation in airplanes, trains or cars. Additionally, in many known types of ski bindings it is not possible to invert the position of the toe unit with the heel unit.
As a partial solution to the aforementioned drawbacks, U.S. Ser. No. 10/181,722 by the same Applicant discloses a structure for regulating and fastening a ski binding. This structure comprises a first front plate and a second rear plate providing support for a toe and a heel unit respectively. A third plate is inserted between the first plate and the second plate, provided with a locking device, which may be activated by the user, that is designed to lock temporarily to a mechanism for coordinating the manual, opposed and axial shift of the first plate and the second plate. Such locking device, although ensuring a fast, easy adjustment of the size, suffers the main inconvenience of not allowing optimal longitudinal flexibility of the ski, particularly near the binding proper. Furthermore, this locking device keeps the position of the centre of gravity unaltered with the change in the actual adjustment. This fact, although being advantageous in many cases, proves to be a limitation should the user desire to change way of skiing by moving the centre of gravity either backwards or forwards, as for example in the case of skiing on fresh snow or in a race.